Trig Substitution Without a Radical

by Kelsey
(Atascadero, CA, USA)

State specifically what substitution needs to be made for x if this integral is to be evaluated using a trigonometric substitution:

I think I need to complete the square in the denominator. I have an answer key, however, I am stuck on how to solve it.

Answer by Pablo:

You are right. Here you need to complete the square. Completing the square you'll get:

After that you're ready to make the trigonometric substitution. I think the most obvious choice is:

This will allow you to simplify the expression a little bit. The messy part is when you need to substitute back, though. But I leave that to you, :).

Return to Trigonometric Substitutions

Click here to post comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Your Doubts and Problems.

Share this page: